This report discusses a limited field test performed on the POS(Platform Orientation System)-406. The function of the POS-406 is to provide a grid, true, or magnetic north reference to ground vehicles. The objective of this test program was to evaluate a magnetic type of north-seeker as the north reference in future FOV (Forward Observer Vehicle) development. Based upon the analysis of data obtained in this test, future FOV planning and development should include both magnetic and gyrocompass types of north references. (Author)